5 New data on geology of the Southern Urals: a concise summary of research after the period of EUROPROBE activity Victor Puchkov Institute of Geology, Ufa Scientific Centre, K.Marx st.16/2, Ufa 450077 Russian Federation. Correspondence to : V.N.Puchkov ( [email protected] ) 10 15 1 5 Abstract. The period of an official activity of the EUROPROBE commission was connected in the Urals with implementation of the URALIDES Program, that stimulated many qualified geologists from the Western research institutes and Universities to come to the region and work with local geologists at topical problems of the Uralian geology. The author tries to answer a question: what interesting results 10 had been obtained in the Southern Urals in the last decade, after most of foreign researchers left the Urals, and how these results correspond to the scientific conclusions that had been reached before. Key words: Urals, EUROPROBE, URSEIS−95, stratigraphy, tectonics, ophiolites, HP metamorphism, plumes. 15 20 2 5 1. Introduction. The decade between 1992 and 2001 was of a special importance for the geology of the Urals. It was characterized by a sudden surge of a research activity from s of geologists and European geoscience communities. They came to see the Urals and apply their skills and knowedge to the better 10 understanding of this famous and extraodnary rich region. Among the main reasons for this “invasion” one may mention the famous “perestroika “ and “glasnost”, followed by the transition to openness of the USSR society and free access to the Urals that previously was almost forbidden to foreigners before the 90s. The first meeting of EUROPROBE in the Urals (May of 1991) took place in the Beloyarsk city, in full view of its “top secret” nuclear power station, and the excursions (guided by me) went from 15 the biggest industrial City, Sverdlovsk, in five directions. It was a time of great plans and optimistic hopes for better understanding and co-operation between nations. The geology, knowing no political boundaries, was a good ground for it. The EUROPROBE program was initiated at the 27th International Geological Congress in Moscow, 1984, as a plan for multidisciplinary research in Europe, including the European part of the 20 USSR and the whole Urals. The aim of the program, inherited from the earlier International Lithospheric Program (ILP), was a better understanding of the structure and tectonic evolution of the lithosphere of Europe and the dynamic processes that controlled its evolution through time. Following and enhancing the ILP plans, EUROPROBE went on with organization of seismic profiles aimed to reveal the deep structure of the most interesting regions. Along with these profiles, great attention was 25 paid to integrated studies of geology, tectonics, geodynamics, geochemistry, petrology and isotopic age of magmatism and metamorphism, paleomagnetiс and geothermal studies, basin analysis and some other topics. Among ten target areas of research, corresponding to ten projects, in which about 30 countries participated; URALIDES was selected as one of the most attractive. Some more research 3 programs were approved and realized later, just before the end of the 10-year EUROPROBE Program or even several years later. The most closely related to URALIDES were the latest TIMPEBAR (Timan -Pechora -Barentsia) and POLAR URALS programs. During the time of EUROPROBE activity, important financial support was received from the 5 European Science Foundation (ESF), which provided a resource for the work of the Science and Management committees and allowed the running of annual workshops for every project, with some travel money budget. Support was also provided by INTAS (The International Association for Promotion of Co-operation of New Independent States). However, the main support was provided by the participants themselves, organized into individual research groups, often multi-national, funded 10 from National Science Foundations and Councils of their respective countries. In the Southern Urals, the main and most expensive task was the >400 km-long URSEIS−95 seismic profile, an integrated seismic experiment. The work was accomplished by co-operative efforts of International consortium (Russia, Germany, USA and Spain), with participation of Spetsgeofizika, Bazhenovskaya Expedition, Bashneftegeofizika (Russia), DEKORP GFZ and Karlsruhe University 15 (Germany), INSTOC Cornell University (USA), ICTJA−CSIC (Barcelona, Spain). A combination of several methods was applied in this study. The CDP combined acquisition by means of vibration and explosion excitation was accompanied by a wide-angle experiment. All acquisition was performed during one field season of 1995, and the following processing and interpretation took several next years. The results were regularly published in the western and Russian literature. The profile was evaluated as 20 an ambitious and successful project (Berzin et al.,1996; Carbonell et al., 1996; Echtler, 1996; Knapp et al. 1996, Morozov, ed., 2001 and others). Along with the geophysical research, significant geological field work was carried out. The most stable and long-lasting co-operation was organized in these years in the Southern Urals between the geologists of the Institute of Geology in Ufa (Ufimian Scientific Centre) and colleagues from the Instituto de la Ciencias de la Tierra Jaume Almera – CSIC, Barcelona; 25 Universidad de Oviedo, Spain; Max-Planck-Institut für Kernphysik, Heidelberg, Germany; Institut für Geologische Wissenschaften und Geiseltalmuseum, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany; Geologisches Institut der RWTH, Aachen; Technical University, Berlin; Institut fur Mineralogie, und Lagerstattenlehre Institut für Geologie, RWTH, Aachen, Germany; Institut für 4 Mineralogie und Geophysik, Ruhr-Universitat, Bochum, Germany; Geological Survey of Finland. More episodically several other teams worked in the Southern Urals, with a participation of geologists from the Institute of Geology and Geochemistry; Institute of Geophysics (RAS), Ekaterinburg; Geological Institute of Moscow(RAS); Moscow State University; Institute of Mineralogy, Miass. They 5 co-operated with geologists from the Universities of Udine, Napoli, Modena and Genova, Italy; Natural History Museum, London; Southampton Oceanography Centre; NERC Isotopу Geosciences Laboratory, Keyworth, Nottingham, UK; Dalhousie University, Canada; BRGM, France; GFZ, Postdam, Germany; University of Granada, University of Jaén Spain; Geological Institute, ETH, Zurich, Switzerland; Uppsala University, Sweden. The teams have published tens of scientific papers in many 10 leading peer-reviewed geological journals. In addition, several special issues of such journals, dedicated to the geology of the Urals were published (Pérez-Estaún, Brown, Gee, eds., 1997; Meyer, Kisters, Stroink, eds., 1999; Brown, Juhlin, Puchkov, eds, 2003). The final events of the main EUROPROBE campaign were publications of two large volumes, partially summarizing the work that had been done (Gee and Stephenson, eds., 2006 and Pavlenkova, 15 ed., 2006). Of special interest, concerning the developments in the URALIDES program as a whole, are the papers of Brown et al., Matte, Kashubin et al., Bosch et al. and Gee et al. in the first of the volumes, and Chapter 4, edited by Puchkov, Kashubin and Pérez-Estaún (2006) in the second volume. The decade of 90s was very difficult for Russian geology. Yeltsin’s political and economical reforms, realized under seemingly attractive slogans of democracy, market economy, privatization, etc, 20 turned out to be an ill-conceived and badly organized adventure and led to destruction of industry (and Geological Survey as well), break-off of business ties, outright banditism, sharp drops of GDP and living standards, low financing and irregular payments of salaries in science and other factors that negatively influenced the level of scientific research in the country. In these conditions, the continued arrival of foreign colleagues that had funding for field research and laboratory analyses permitted the 25 continuation of scientific studies of the Urals geology at a relatively decent level and progress. Although the USSR geologists belonged to one of the strongest professional communities in the world, providing knowledge of 1/6 of the world land area with its richest deposits, the co-operation with so 5 many representatives of different, English-speaking scientific schools enriched them with many ideas of modern science and provided an impetus for a further development. The aim of this paper is not to describe the achievements of this period, which are well known and easy to find in published English-language literature, and probably deserve a special analysis, but to 5 summarize, at least partially, what interesting research that has been done in geology of the Southern Urals in the latest decade (2006−2016). 2. Stratigraphy. Although the stratigraphy was not the main focus of the URALIDES project, it had important implications for conclusions made in the structural and geodynamic studies of the 10 Urals. 2.1. Precambrian. The Precambrian stratigraphy was always a priority with geologists of the Southern Urals, because the ~15 km-thick section of weakly metamorphosed Proterozoic sediments of the Bashkirian meganticlinorium was accepted as the stratotype of the Riphean, and is still part of the Russian Stratigraphic Code and General Stratigraphic Scale of Russia (GSSR), being widely used for 15 geological mapping and prospecting.